Through the goggles of hindsight, it was all over with my birth mother - I'll call her Bonnie - by Christmas 2006. The year she sent me The Watch. A watch among watches. White leather strap, arctic face the size of a large macaroon, silver detailing, circumnavigated with a twinkling aurora of diamantes. I may have gasped when I opened the box. "Oh my god," I cried, flashing my wrist at anyone who'd listen. "My mother has sent me bling."

Every compliment I got - and that watch, which was visible from the moon, got plenty - was a validation that Bonnie and I had "connected". Obviously she "got" me in a way that my parents, Arthur and Norah, the ones who adopted and raised me, didn't.

I love my adopted parents dearly, but their approach to gifts for their only child appeared to combine, in equal parts, panic and finding things by feel in a darkened department store. A road atlas! A crimplene dress! A painting of a tiger! I have no idea who, in their imagination, they were buying for. I often felt that I was written in a language they couldn't read. One birthday they handed me a box containing a pearl on a chain, Dad saying, "Now, we know you don't wear gold. Or pearls. But we thought you'd like this, anyway."

So, yeah, like Meatloaf, I was glowing like the metal on the edge of a knife. I rang Bonnie, who lives in a small, green, cobbled town in the south of England, to give thanks.

"I love it, I love it, I love it!" I said.

"I knew you'd like it," Bonnie said, before adding, "because I know you like attention."

Pow. Right in the kisser.

You'd think, from all the forced adoption documentaries, TV series and official apologies flying around, that Bonnie would have been thrilled to have me back in her life. Her lost lamb. THRILLED. Not so much, as it happens.

In 2000, when we first met shyly over a London pub lunch and what turned out to be our major shared enthusiasm, red wine, I was primed to be Very Understanding. I knew the bones of her story; how she'd taken a summer waitressing job in a Butlins holiday camp to avoid telling her parents, went into total denial about being pregnant, and was eventually introduced to Norah and Arthur, who ran a Norfolk pub and, er, took me off her hands. You could just do that in the '60s.

I was expecting a teary variation on "I had no choice" and "I didn't want to", but what I got was, "I was determined to get rid of you". Bonnie wasn't being harsh, just supremely pragmatic. She was 17 and wanted her life back. I'm down with that.

It can't have been a walk in the park getting pregnant at 17 to the local iron-mongering lothario - especially when you're the youngest of nine and have no privacy. The decisions she made, entirely on her own, smacked of pure survival instinct.

She stayed on in Norah and Arthur's attic for a week after my birth before returning home, keeping quiet, and getting on with it. She spent that week ferociously chain-smoking (apparently setting my hair on fire) and not breastfeeding.

"I didn't want to bond," she said.

Like I say, goggles of hindsight.

It wasn't easy for self-conscious Bonnie, me turning up - as an Australian, of all things. An extroverted, tall, red-haired one at that, with the lack of inhibition that comes from escaping Britain's throttling class system as a teen and running like the proverbial wind. The only thing we had in common is our idiosyncratic nose.

From her perspective, I radiated "LOOK AT ME", while Bonnie had spent a lifetime pretending I had never happened. Awkward.

She showed me her handful of black-and-white pregnancy photos, which were noteable inasmuch as I wasn't in any of them. There was one of Bonnie behind a couch, modest beehived head popping over the top, another with her belly twisted out of shot, another with her peering from behind a potted shrub. I began to understand why I came out the womb hoping to be noticed.

I wonder if I left tracking her down too late. There was no urgency on my part. Mum and Dad always told me I was adopted, so I was never galvanised by that daytime-soap "I knew you weren't my real parents" moment. The Scott-Normans, a tidy trio, moved to Perth when I was 17, and geography did the rest.

Bonnie, meanwhile, girded herself for me turning up when I was 18. And then 21. And wondered about me when her two sons were born, and, finally, when she held her first grandchild. By the time I arrived, aged 39, long past the point where I might reasonably have been expected, she had doubled down on her secret so many times her pain was impenetrable.

So, no, not "thrilled". But to her credit she got on with it - even though, no surprises here, "attention" puts her into encephalitic shock, and she finally had to reveal me to her large, friendly, insanely curious family. It was like being sniffed to death by two dozen bounding Labrador puppies. I loved it. She hated every second.

I really like Bonnie, and she did "see" me. She just didn't like everything she saw. We managed a decade of sometimes close, ultimately dwindling, mostly long-distance connection. I guess, in the end, having the same nose wasn't enough. So she cut me loose a second time.